SiOC fibers can also be obtained by spinning and pyrolysis of siloxane or polysiloxane with carbon functional group and silica sol. It has a tetrahedral structure with Si, u and C atoms connected by covalent bond. It can also be regarded as a product of the substitution of the atom part of the silicon oxygen tetrahedron structure of SiO2 by C atom. Because the substituted u atom can only bond with two Si atoms, and the C atom can bond with four Si atoms, the introduction of C atom makes the rigidity of the silicon oxygen tetrahedron skeleton stronger. Therefore, SiOC fiber is more rigid than silicon oxide fiber It has better high temperature stability, high temperature creep resistance, chemical stability and mechanical properties. The sol-gel reaction of metal salts or metal alkoxides with siloxane can simultaneously introduce metal elements (such as Al, Ti, Zr, Hf, etc.) into SiOC fibers. These heterogeneous elements can form high-temperature phases such as metal oxides or metal carbides during pyrolysis or heat treatment. On the one hand, these phases have a high melting point; on the other hand, the formation of these phases can hinder the diffusion of atoms, inhibit the material failure caused by carbothermal reduction in high temperature environment, and further improve the high temperature performance of SiOC fiber. The results show that adding a small amount of Zr (1% ~ 2%) to SiC or SiCN ceramic fiber can obviously improve the high temperature stability and high temperature oxidation resistance of the fiber.

Using zirconium dichloride as zirconium source, ethyl orthosilicate and dimethyldiethoxysilane as siloxane precursor and ethanol as solvent, the meter grade pzso fiber was obtained by liquid spinning using the hydrolysis condensation reaction of zirconium oxychloride and siloxane. The optimal spinning condition is HZO / Si = 0.59, Zr / Si = 0.02. Pzso fiber was pyrolyzed in hydrogen at 1000 ℃ for 1h to form sizroc ceramic fiber. The corresponding ceramic yield was 84.7%. The surface of sizroc fiber is uniform and smooth, the cross section is compact, and the circular cross section structure of pzso fiber before pyrolysis is maintained. The sizroc ceramic fiber has excellent high temperature stability and can be stabilized to 1500 ℃ in inert atmosphere.